Method of attaching sutures to shanks of surgeons&#39; needles



Nov. 12, 1946. G. H. J. BAULE 2,411,079

METHOD OF ATTACHING SUTURES TO SHANKS OF SURGEQNS NEEDLES Filed Sept. 9, 1944' ilillll 4 INVEN TOR.

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Patented Nov. 12, 1946 OFFICE METHOD OF ATTACHING SUTURES TO SHANKS OF SURGEONS NEEDLES Gerhard H. J. Baule, Salina, N. Y.

Application September 9, 1944,-Serial No. 553,394

1 Claim. 1

This invention relates to surgeons needles and has for its object a method of attaching cords or sutures to the shanks of needles leaving a maximum amount of metal in a shank of minimum diameter with a suture of maximum diameter, thus producing a shank of maximum strength and minimum outer diameter with the suture of maximum diameter anchored therein.

The invention consists in the method and steps hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanying drawing in which like characters designate corresponding parts in all the views.

Figure 1 is an elevation, partly in section, on an enlarged scale, of a needle with suture or cord attached.

Figure 2 is an elevation of the shank of the needle, partly in section on a greatly enlarged scale illustrating the enlarging or expanding of the outer end portion of the shank.

Figure 3 is a sectional view illustrating the complete formation of the blind axial recess in the expanded portion and the adjacent unexpanded portion of the shank with the recess of substantially the diameter of the suture to be attached,

Figure 3 also showing another step which may be omitted, of tapering the walls of the entrance or mouth of the recess into a funnel shape extending from an intermediate point in the bore of the expanded portion to the outer end of the shank.

Figure 4 is a view similar to Figure 2 illustrating a slight modification of the method, wherein an axial bore is formed before the expanding op eration but the blind recess not completed until after the expanding operation.

Figure 5 is a. view showing the shank after the expanding operation is performed on the shank shown in Figure 4.

Figure 6 is a view similar to Figure 5 showing the completion of the blind recess with its walls machined out throughout the length thereof to the diameter of the suture.

Figure 7 illustrates the forming of the funnelshaped mouth for the expanded portion of the recess shown in Figure 6.

Figures 8 and 9 are views similar to Figure 1 of modified forms of the needle produced by this method.

It will be understood that surgeons needles are necessarily of extremely small diameter, and the suture must be firmly attached thereto and that when the suture is attached thereto, the shank' must be smooth or free from comers or crevices, and also that the shank of minimum diameter for 2 the maximum diameter of suture must not be unduly weakened so that the needle breaks when being used. The breakage of needles, which are of but a few thousandths of an inch in diameter,

has heretofore been not an uncommon occurrence and sometimes is the rule rather than the exception.

This method of attaching sutures to the shanks of needles includes expanding an outer end portion of the shank to a larger diameter than the adjacent inner portion; forming a blind axial recess in the shank of substantially the diameter of the suture to be attached thereto, the recess extending through the expanded portion and well into the unexpanded portion of the shank; placing the suture in the recess and contracting the expanded portion, so that its inner diameter is less than the suture and its outer face substantially flush with the outer face of the unexpanded portion of the shank. The axial recess may be partly formed before the outer portion of the shank is expanded and completed after the expanding operation or may be completely formed after the expanding operation.

I designates the needle; 2 the shank thereof, and 3 the cord or suture attached thereto. In Figures 2 and 3, the outer. end portion] of the shank is expanded before the blind recess is formed. It may be expanded in any suitable 3o manner, as by applying an axial compressing force to this shank while holding the inner end portion 5 of the shank from expanding and controlling the expanding of the outer end portion 4 by means of suitable dies, this being something of a forging operation. The end of the shank is provided with a centering hole 6 for facilitating drilling operations. After the shank is formed up, as shown in Figure 2, a blind recess I is drilled out, the diameter thereof being substantially that of the suture 3, so that the suture fits the recess when inserted therein. The expanded portion is then contracted, so that its internal diameter is less than that of the suture and its peripheral surface substantially flush with the peripheral surface of the inner unexpanded portion 5 of the shank, so that a head 8 is provided at the inner end of the suture, fitting the inner end portion of the recess and anchoring the suture in the recess. The suture, when placed in the recess, is inserted as far as or to near the inner end wall which bounds the recess. For the purpose of preventing lateral bending or breaking strains at right angles to the axis of the suture when pulling force is applied to the needle and suture with the needle turned at an angle to the suture, the

entrance end of the recess is formed conical or beveled or tapered, as at 9 (Figure 3), the conical or tapering portion starting from a point midway between the ends of the bore of the expanded portion, and flaring outwardly toward the outer end of the expanded portion. When the expanded portion is contracted onto the suture, the walls of this entrance or conical portion are also contracted to fit onto the suture, as shown in Figure 1, and also in Figures 8 and 9.

As seen in Figures 4, 5, 6 and 7, the shank 2 may be first formed with an incomplete blind recess Ill, and then the outer portion 4 of the shank expanded and the blind recess 1 completed by boring it out to a diameter substantially that or the suture. The suture is then inserted in the recess and the expanded portion contracted into a diameter-less than the suture. The entranceend of the recess is also tapered at 9 so that the resulting joint is the same as that shown in Figure 1.

In Figure 8, a modification of the joint between the shank and the suture is shown, in which the shank is first formed with a cylindrical blind recess and then expanded into conical form with the larger diameter at the outer end of the shank, making the recess conical, the conical recess then bored out substantially cylindrical to the diameter of the suture; the suture inserted, and the outer conical portion contracted onto the suture to its outer original diameter, thus forming the recess conical with its end of smaller diameter toward the outer end of the shank, all as described in connection with Figures 4, 5, 6 and '7, or the solid shank may be expanded or upset into conical form with the end of larger diameter at the outer end of the shank, and the recess bored out to substantially the diameter of the suture;

'the suture inserted and the conical portion contracted, as described in connection with Figures 2 and 3.

In Figure 9, the initial expansion is conical, as described in connection with Figure 8, but to a greater diameter than in Figure 8 and the wall of v the bore bored out in a plural number of steps of different diameters. Thus, when the expanded portion is contracted to its original external diameter and its internal diameter to less than the diameter of the suture, the suture is contracted at a plurality of points or rings.

In the form shown in Figures 4 and 5, the piece is expanded from the form shown in Figure 4 to that shown in Figure by a radial expanding 4 force applied to the interior of the outer end por-. tion of the shank in which the partly completed blind recess is pre-formed.

In any form of the invention, a portion of the shank is expanded into a diameter greater than its original diameter and this portion contracted after being formed with a blind recess, into a diameter less than the diameter of the suture and with its peripheral surface back into its original diameter, so that it is flush with the adjacent portion of the shank. Thus, a suture is firmly anchored to the needle without unduly weakening the needle, that is, removing a minimum of metal to form the blind recess, and also owing to the contracting of the expanded portion, the recess may be so formed, as not to require grinding and minute fitting of the suture to fit the recess, and

as these sutures are practically a. thread, this feature is a great desideratum in the production of surgeons needles with the sutures attached.

Also, the needles may be formed of minimum diameter with the maximum amount of metal an with the suture of maximum diameter.

What I claim is:

The method of attaching sutures to the shanks of surgeons needles including expanding the outer butt end cylindrical portion only of the needle shank radially to a larger diameter than the remaining portion, boring a blind axial cylindrical recess in said outer end portion of the shank through the expanded portion and into the adjacent unexpanded portion of the shank, the recess being of substantially the same diameter as the'suture, whereby the cylindrical wall of the portion of the recess in the unexpanded portion of the shank adjacent the expanded portion is of less thickness than the wall of the recess in the expanded portion; placing the suture in the recess approximately to the inner end wall of the recess and contracting the expanded portion radially onto the suture, so that the inner diameter of the contracted portion is less than that of the normal diameter of the suture and so that the outer face of the now contracted portion is flush with the outer face of the adjacent unexpanded portion of the shank, whereby the portion of the suture in the inner end portion of the recess provides an anchoring head for the suture and the wall of the contracted portion is thicker than the wall of the inner end portion of the recess, and provides an internal collar against which the head pulls.

GERHARD H. J. BAUL 

